Lifting jack



LIFTING JACK Filed Nm). e, 1924 Patented Oct. 27, 1925. i i

.UNITED STATES 1,559,098 PATENT oFFicE.

ARTHUR C..HOPKINS, 0F NILS, MICHIGAN, ASSIGNORTO NATIONAL STANDARD A COMPANY, OF NILES, MICHIGAN.

LTFTING JACK.

Application led November 6, 1924. Serial. No.. 748,104.

To all whom z't may concern.'

Be it known that I, ARTHUR' C. HOPKINS,

a citizen of the United States, `residing at Niles, county of Berrien, State of Michigan, 5 have invented certain new and useful Improvements in Lifting Jacks, of which the following apeci-iication. This invention relates to improvements in lifting jacks] The Amain objects of this invention ares First, to provide an improved lifting jack in which the frameis so constructed` and the wheels so arranged that strain upon the wheels is minimized and a three-point-support for the load provided.

improved lifting means which is very poweri ful.

Third, to provide in a lifting jack kan improved actuating means for the lifting member. .y

Objects relating to detailsv and economies of construction and o eration will definitely appear from the detalled :description to follow.

I accomplish the objects'v of my invention by the devices and means vdescribed in the following specification. The invention is clearly definedand, pointed out in the claims. .l

A structure which is a preferred embodiment of my invention is clearly illustrated in the accompanying drawing,- forming a' part of this application, in which:

Fig. I is a lan View of my improved lifting jack wit the actuating flever,.which also constitutes a handle, partially broken awa.

Flg. II is a longitudinal section on a line correspondi to the broken line 2-2 of Fig. I, theliting member being shown in its lowered 4position by full lines and in elevated position bydotted lines.

Fig. III is a fragmentary" view partially in section on a line corresponding to line 3-3 vof Fig. II.' Fig. IV is an enlarged detail side elevation of the inner end of the actuating lever, showing the 'relation of the payvls mounted thereon to the driving ratchet, the'pawls being shown in engagement by full lines and in disengaged position by dotted lin-es.

In the drawing similar reference chiaracters refer to similar parts throughout the several views, and the sectional views are Second, to providein a lifting jaclianvtaken looking in the direction of the little arrows at the ends of the section lines. 'f

Referring to the drawing, the y'frame' of the embodiment illustrated comprises a pair of side members l having parallel portions at its front and rear ends and vfo'rwardly divcrging portions between thel parallel portions.

At the front end of the frame vis a frame# like cross member 2 disposedbetween andi The rigidly secured to the side members. side members are further connected by the cross rods 3 disposed through the spreaders 4. At their rear ends the side members are provided with lateral arms 5. The standards 6 yof the caster wheels 7 are secured to` vthese, arms.

l The front wheels 8 are mounted on an axle 9 which is mounted within thefront "cross member 2 of the frame by means of the longitudinallyand centrally disposed pivot 10.

f he vframe has a three-point support, the

front wheels adjusting themselves to any out the throw of the lever by means of the link 15 which is pivoted to the head member at 16 vand to the frame at 17. The pivots 14 and 16 and 12 and 17 respectively are so arranged in relation to each other that the link is in parallelrelation to the lifting lever.

At the rear end of the frame, I journal a support 18 for the `screw 19, the support being journaled so that it has a rocking movement between the frame'side members. The screw 19 hasa spherical head 20 at its front end engaging a socket 21 in the lifting lever 11, the socket being disposed below the lever ivot 12 which constltutes the fulcrum for t e lever, the screw being the power applying means.

On thls screw is a ratchet wheel 22 having a hub 23 of considerable length in threaded-engagement with the screw. A

thrust bearing 24 is interposed between the support 18 and the screw. The screw is enf" gaged by al spline 25 on the support 18.

The ratchet is driven from the actuating lever 26 which isforked at 27 and pivoted at 28 to the depending ears 29 on the support 18. Each arm of the levercarries a pawl 30, the pawls being adapted to act on the ,ratchet on opposite sides of the screw. TheV pawls are provided with weights 3l which tend to hold them in engagement with the ratchet wheel. To selectively disengage the pawls, I piovide a pawl disengaging member 32 which is pivoted at 33 on the cross piece 34 extending between the arms ofthe lever, this control member 32 being adapted to engage the arms 35 on the pawls and when engaged therewith, support the pawls in inoperative position as shown by`I dotted lines in Fig. IV. The ends of the control member 32 are disposed through slots 36 in the arms of the lever.

An adjusting rod 37 for the pawl control member 32 is arranged through the handle,

of the actuating lever 26 and provided with a finger piece 38.

With this arrangement of parts, I provide a frame which is adapted to su port loads without undue strain upon the rame. The power` or actuating means may be easily operated to raise or lower the jack and is very powerful.

I have illustrated and described my i1n` provements in f, bodiment. I have not attempted to illustrate certain modifications and adaptations which I contemplate as I believe the disclosure made will enablezthose skilled in the art to embody or adapt my improvements as may be desired. 1

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

l. In a liftingI jack, the combination of a frame comprising side members having parallel portions at their front and rear ends and intermediate forwardly diver-ging portions, said side members 'having laterally projecting arms at their rear ends, caster wheels mounted on said arms, a frame-like cross member disposed between the front parallel dportions of said side members, an

axle pivotally mounted on said cross mem ber, the pivot for said axle being disposed centrally and longitudinallyof the frame, wheels on saidsaxle, a lifting lever pivotally mounted between the rear parallel portions ofsaid frame side members to project forwardly and adapted to collapse between the saine, a head member pivotally mounted on said lifting lever, a head supporting link pivotally mounted between said side memers and pivotally connected to said head member in parallel relation to said lifting lever whereby the head member is support` ed in upright position throughout the throw simple and practical emi "of the lifting lever, a screw support journaled between the rear ends of said, side members for rocking movement, an actuating screw mounted on said support to engage said lifting lever below its pivot, a driving iiember disposed in front of said screw support and having a threaded engagementv with said screw, and means for rotating said driving member in either direction.

2. In a lifting jack, the combination of a frame comprising side members, caster wheels at the rear ends of said side inembers, a cross member disposed between the front ends of said side members, an axle pivotally mounted on said cross member, the pivot for said axle being disposed cen trally and longitudinally of the frame. wheels on said axle, a lifting lever pivotally mounted between the rear ends of said frame side members to project forwardly and adapted to collapse between the same, a head member pivotally mounted on said lifting level', a head supporting link pivotallyr mounted between said side members and pivotallv connected to said head member in parallel relation to said lifting lever where` by the head member is supported in upright position throughout the throw of the lifting lever, a screw support journaled between the rear ends of said side members for rocking movement, ani actuating screw mounted on said support to engage said liftinglever below its pivot, a driving member disposed in front of said screw support and having a threaded engagement with said screw,l and means for rotating said driving member in either direction.

3. In\ a lifting jack, the combination of a frame comprising side members having parallel portions at their front and rear ends and intermediate forwardly diverging portions, said side members having laterally projecting arms at their rear ends, caster wheels mounted on said arms, a frame-likt cross member disposed between the front parallel portions of said side members, an axle pivotally mounted` on said cross merrber, the`pivot for said axle being disposed centrally-and longitudinally of the-frame, wheels on said axle, a lifting lever pivotally mounted between the rear parallel portions of said frame side members to project forwardly and adapted tocollapse between the same, a head member pivotally mounted on said lifting lever, a head sup orting link pivotally mounted between sai( side members and pivotally connected to said head member in parallel relation to said lifting lever whereby the head member is supported in upright position throughout the throw of the liftingr lever, and means for actuating said lever.

4,. In a lifting jack, the combination of a frame comprising side members, caster wheels at the rear ends of said side members,

a cross member disposed between the 'front ends of said side members, an axle pivotallj7 mounted on said crossmember, the pivot for lsaid axlebeing disposed centrally and longitudinallyof'the frame, wheels on said axle, a lifting'lever pivotally mounted b'e 'tween the rear ends of said frame side memlation to said lifting lever where/bythe head` member is supported in upright ,position throughout the throw of the lifting lever,

' and means for-actuating said lever..

. 5. In a lifting jack, the combination of a frame comprising side members having parallel portions at their front and rear ends and intermediate forwardly diverging 'ortions, said side members having4 laterally projecting arms at their rear ends, caster wheels mounted on said arms, a frame-like cross member disposed between ythe front parallel portions of said side members, un axle nivotally mounted on said cross mem'- ber, the pivot for saidaxle being disposed centrally and longitudinallyof the frame, wheels on said axle, and lifting means mounted on said frame.

6. In a lifting jack, the combination of a.

frame, a lifting lever pivotally mounted on said frame, a headl member pivotally mounted onsaid lifting lever, ahead supporting link pivotally mounted on .said frame and pivotally connected to said head member in parallel relation to fsaid lifting lever whereby the head member is supported in upright position throughout the throw of the lifting lever, a screw support on said frame, an actuating screw mounted on saidsupport to coact with said lifting lever, a'

driving member `for said screw having a threaded engagement therewith, and means for rotating said driving member in either direction.

7. In a lifting jack, the combination of a frame, a'lifting lever pivotally mounted on.

' said frame, a screw'support on said frame,

an actuating screw mounted on said support to coact with said liftinglever, a driving member for said screw having a threaded 'engagement therewith, and means for rotating said driving member in either direction.

8. In a lifting jack, the combination of a frame comprising horizontally l disposed spaced side members, a lifting lever pivotnlly mounted between said side members to collapse between the same, an actuatingv screw support `journaled between the side members 'for rocking movemenhan actuating screw disposed horizontally through said support and 'engaging the said lifting lever below its pivot, a. driving ratchet frame having .threaded engagement Iwith said screw, a thrust bearing between said idriving lever and said screw support, a `forked actuating lever pivotally mounted on the under side of'said support, a pair 'of pawls mounted on the arms of said actuating lever to coact with said ratchet on opposite sides of its axis', a pawl control member pivotally mounted on said actuating lever, the arms of said lever having slots therein to receive said control member, said pawls having screw support journaled between the side*E members for rocking movement, an vactuat` ing screw disposed horizontally through said support and "engaging the said lifting lever below its pivot, a driving ratchet having# threaded engagement with said screw, a

thrust bearing between said .driving lever 'and said screw support, an actuating lever pivotally mounted on the underside of said support, a pair .of pawlsmounted on said actuating lever to coact with said ratchet on opposite sides of its axis, and means for supporting either of said pawls in imperative position,

10. In a lifting jack, the combinationof a frame comprising horizontallywdisposed spaced side members, `a lifting lever'pivotally mounted between said side membersto collapse between the same, a head member pivotally mounted on said lifting lever, a hea'd supporting link pivotally mounted between -said side members and pivotally connected to said head member in parallel rela.- tion to said lifting lever whereby the head is maintained in upright position through` out the stroke of the lifting lever, an actuating screw support journaled between the side members for rocking movement, an actuating yscrew i disposed horizontally through said support and engaging the said lifting lever below its pivot, a driving ratchet lhavingthreaded engagement with said screw, a thrust bearing'between said driving lever`l and said screwsupport, an

under side of said support, a` pairiof pawls mounted on said actuating lever to coact f 11. In a lifting jack, the combi a frame 'comprising horizontally' ,disposed vspaced side members, a lifting lever pivotnation of A actuating lever' pivotally` mounted on the with said ratchet on opposite sides of its '125 ally mounted between said side members to'V collapse between the same, an, actuating screw support journaled between the side members for rocking movement, and an actuating screw .disposed horizontally through said support and engaging the said lifting lever below its pivot.

l2. In a liftin; r jack, the combination of I a frame, a lifting lever pivotally mounted mounted on said frame to coact with said lifting lever, a driving ratchet having threaded engagement with said screw, 'au actuating lever pivotally mounted on said frame, a pairl ofpawls mounted on. saidl actuating lever to coact with said ratchet on opposite sides of its axis, and a pawl control member adapted to disengage either of said pawls.

13. ln a lifting jack, the combination of a frame, a lifting lever pivotally mounted on said frame, an actuatingr screw mounted on saidI frame to coact with said lifting lever, a driving ratchet having threaded eugageinent With said screw, an actuating lever pivotally mounted on said frame, a pair of pawls mounted on said actuating lever to coact with said ratchet on opposite sides of its axis, and a pawl control member adapted to disengage either of said'pawls.

14. In a lifting jack, the combination olt a frame, a lifting lever pivotallvmounted on said frame, a head member pivot-ally mounted on said lifting lever, a head sup porting link pivotally mounted on said frame and pivotally connected to said head member in parallel relation to said lifting lever whereby the head is maintained in upri ht positionV throughout the stroke of the liting lever, and an actuating screw mounted on said frame to coact with said lifting lever.

In witness whereof I have hereunto set my hand.

' ARTHUR o. HOPKINS. 

